Cairo.Clip (gb.cairo)

Establishes a new clip region by intersecting the current clip region with the current path as it would be filled by Cairo.Fill and according to the current fill rule (see Cairo.FillRule).

After Cairo.Clip, the current path will be cleared from the cairo context, unless the Preserve argument is TRUE.

The current clip region affects all drawing operations by effectively masking out any changes to the surface that are outside the current clip region.

Calling Cairo.Clip can only make the clip region smaller, never larger. But the current clip is part of the graphics state, so a temporary restriction of the clip region can be achieved by calling Cairo.Clip within a Cairo.Save / Cairo.Restore pair. The only other means of increasing the size of the clip region is Cairo.ResetClip.